Unknown Plugin Board

I got whispered by "blizz01" that said the system detected an unknown plugin board and that I should visit "". I have no clue what this even means. Is it just a scammer? And should I be worried if I have an authenticator?

Change your account password immediately. It looks like the account is already locked, most likely as an attempt to access it from another geographical location was made. An email was sent to the registered address explaining the procedure.